Effect of vanadium doping on ferroelectric and electrical properties of Bi3.25La0.75Ti3O12 thin film

Bi3.25La0.75Ti3O12 (BLT) and V-doped BLT (BLTV) thin films were prepared on Pt/Ti/SiO2/Si substrates by a pulsed laser deposition method. The effects of V doping on ferroelectric and electrical properties were investigated by polarization-electric field hysteresis loops and leakage current-voltage measurements. BLTV single phases were confirmed by X-ray diffraction. Remnant polarization was increased and the leakage current density was decreased by V doping. The leakage current density of BLT thin films suddenly increased at 100 kV/cm while that of BLTV thin films increased at the higher electric field of 160 kV/cm. The power law relationship J alpha E-n of current density vs. applied electric field is estimated to be J alpha E-2.0 for BLT and J alpha E-1.0 for BLTV thin films. The leakage current of the BLT/Pt junction can be explained by space-charge-limited current. However, that of the BLTV/Pt junction was characterized by the Schottky emission behavior.